The present invention relates generally to the field of audio and/or video (hereinafter “AV”) data stream delivery over wireless communication networks, and in particular, although not exclusively, to the delivery of time-critical streams to mobile communications devices.
Recent years have seen a huge increase in the form and function of mobile communications-enabled devices, coupled with an even greater increase in the volume of AV content available for access (whether downloaded and stored or watched/listened to “live”). A particular problem area relates to accessing content using a mobile data network, such as a 3G network accessed from a Smartphone or laptop. If a subscriber is moving while streaming content, or downloading a large file, then the network must manage the subscriber's transition between cells of the network.
One approach to managing the transition is directed to a method and system for reducing service interruptions to mobile communication devices. In the system described, context information (in the form of location and speed/direction data) associated with a wireless mobile device is used to determine a potential occurrence of a network disruption, for example a railway tunnel or the boundary between two networks. Upon determining a potential occurrence of a network disruption, the system makes a prediction as to the future data that may be desired by the mobile device and then causes an increase in the bandwidth available for data transfer to the mobile device, such that the predicted future data is pre-emptively transferred to the mobile device. The increase in bandwidth available for data transfer is intended to allow sufficient data content to be pre-cached by a memory cache controller of the mobile device so as to provide continual data content to the user during a network disruption. A further example of pre-emptive caching within a mobile device based on a predicted location of that mobile device.
A problem with the above approach is that firstly it just addresses potential breaks or delays in the transmission of the data stream from network to mobile user, and does not deal with the delays that can arise when an ongoing request for a continuous data stream delivery is transferred from one network to another, or even between transmission sources on the same network. Secondly, it requires a relatively large amount of local memory space to be kept free within the mobile device to receive and cache the temporary data.
It is therefore an object of the present invention to provide a means to minimise delays in the supply of streaming content to a user moving through a series of content delivery sources.